Adult Cardiac Valvular Disease for the General Radiologist
Mark M. Hammer, MDKareemMawad, MDFernando R. Gutierrez, MDSanjeevBhalla, MD
All authors have disclosed no relevant financial relationships.Address correspondence to: S.B.,CardiothoracicRadiology Section, MallinckrodtInstitute ofRadiology, WashingtonUniversity School ofMedicine, Box 8131, 510 SKingshighwayBlvd, StLouis, MO63110 (e-mail:[email protected]).
Contents
Learning objectivesIntroductionOverview of cardiacvalvularanatomyMitral disease: regurgitation, annular calcifications, stenosisAortic disease: stenosis, regurgitation, calcificationsTricuspid disease: regurgitationPulmonic disease: stenosisEndocarditis andvegetations
LearningObjectives
Recognize the normal anatomic position of cardiac valves on frontal and lateral chest radiographs.Describe the changes in cardiac chamber sizethat are relatedto aortic, mitral, and tricuspidvalve stenosis and the changes that are related to regurgitation.Listfeatures ofaortic, mitral, and tricuspidvalvulardisease that are visible at chest radiography and computed tomography (CT).
Introduction
Valvular abnormalities underlie a large fraction of cardiac disease casesModerate to severevalvulardisease is present in 8.5% of adults aged 65–74 years and 13.2% of adults 75 years or olderPresence of avalvularabnormality may affect how other medical conditions (eg, cancer) should be treatedAlthough cardiac function andvalvularabnormalities are best evaluated with echocardiography or cardiac magnetic resonance (MR) imaging, many features ofvalvulardisease are apparent at chest radiography and CTRadiologists may be the first to discover cardiacvalvulardisease and can help in its evaluationDiseases affecting each cardiac valve, from the most to the least commonly affected, are discussed in this presentation
NormalValvularAnatomy
Posteroanterior(PA) and lateral chest radiographs in a patient with normal cardiac valve anatomy show the locations of thetricuspid(T),mitral(M),aortic(A),and pulmonic (P,dotted-dashed circle) valves.
P
T
M
A
P
Click to viewanimation
Mitral Regurgitation
Has multiple causes, most commonly:Mitral valveprolapseInfarct involving a papillary muscleDilatedcardiomyopathyRheumatic heart diseaseImaging demonstrates sequelae of mitral regurgitation:Left-heart failureLeft-sided chamber dilatationEnlargement of pulmonary arteries because of venous hypertension
Schematics demonstrate normal mitral valve function(I)and the effects of mitralregurgi-tation(II–IV).Regurgitantvolume(II)expandsthe left atrium(III)and recirculates into the left ventricle, which becomes dilated(IV).Red arrows = direction of flow.
I
III
II
IV
Mitral Regurgitation
PA radiograph obtained ina 60-year-old woman withcongestiveheartfailure shows an enlarged left atrium lifting theleftmainstembronchus,and enlargedpul-monaryarteries (within blue-shaded ovals). Thesefindings are characteristic of severe mitral regurgitation.
Click to view animation
Mitral Regurgitation
LA
LV
RA
PA chest radiograph shows asymmetric edema in the upper lobe of the right lung, a feature resulting from acutemitralregurgitation. The asymmetric edema is related to the regurgitant jet directed toward the right superior pulmonary vein. Acute mitral regurgitation is often seen in the setting of myocardial infarction with papillary muscle rupture.
Axial CT imagesin a patient with chronic mitral regurgitation showdilatation of the left atrium (LA,top)and leftventricle(LV,bottom). Theright atrium (RA,bottom)is also dilated from tricuspidregurgitation.
Mitral Annular Calcifications
Calcific deposition within the fibrous mitral valve annulus is a common finding due to aging.It is thought to be produced by a mechanism similar to that leading toathero-sclerosis.It is typically not associated with mitral valve dysfunction.
Lateral chest radiograph shows mitral annular calcifications in a 76-year-old man.
Mitral Annular Calcifications
PA (top left) and lateral (top right) radiographs and axial CT image (bottom left) showcalcifi-cationsof themitralannulus,coronary artery,andaortic valve.
Mitral Stenosis
Virtually always associated with a history of rheumatic heart diseaseRarely from endocarditis, congenital malformation, or mitral annular calcificationConsequent pulmonary venous hypertensionLeft atrium enlarges because of pressure overloadCalcified left atrium seen in rheumatic heart diseaseCalcifications in the left atrium can also be seen with chronic, calcified thrombusLeft ventricle is typically not affected, in contrast to mitral regurgitation
Axial CT images show calcified mitral valve leaflets (top, arrows) and a dilated left atrial appendage (bottom,LAA)in a 64-year-old woman with severe mitral stenosis.
LAA
Mitral Stenosis
Axial CT images (same patient as previousslide) showright ventricular hypertrophyandpulmonary arterial enlargementdue to pulmonary hypertension.Pulmonaryvascular redistributionis evident, with pulmonary arteries larger than corresponding bronchi.Left ventricular hypertrophydue to aortic stenosis is also seen.
Click to view animation
SevereMitral Stenosis
PA and lateral chest radiographs obtained in a 44-year-old man with a history of mitral stenosis and rheumatic heart disease who presented with shortness of breath show an enlarged, calcifiedleft atriumwith splaying of thecarina,mitral valvereplacement,andpulmonary vascular redistribution(upper lobe vessels larger than lower lobe vessels).
Click to view animation
Aortic Stenosis
Common in aging populationsCaused by calcification of leaflets in a similar mechanism to aortic atherosclerosisA bicuspid aortic valve (1%–2% of population) is predisposed to early stenosisDense calcification of the aortic leaflets is closely associated with severe aortic stenosisIn one series, patients with moderate to severe calcifications at CT had a 60% chance of aortic stenosis, according toKooset al (2006)Calcifications seen at chest radiography are even more strongly indicative of severe stenosis
Axial contrast-enhanced CT images at the level of the aortic root in a 54-year-old woman (top) and a 67-year-old woman (bottom) show dense calcifications of the aortic valve (arrows).
PA (above left) and lateral (above right) radiographs show a calcifiedaortic valvein a 63-year-old man with dyspnea on exertion.
Aortic valve calcifications(arrows) areseen also on coronal (above left) and sagittal (above right) chest CTimages obtained in the same patient.
Severe Aortic Stenosis
Click to viewanimations
Aortic Stenosis
Outflow obstruction produces hypertrophyof the left ventricleVentricular hypertrophy may be overestimated on non–cardiac-gated images obtained during systoleLeft ventricle is not typically dilated until a late stage of diseaseEctasia or aneurysmal dilatation of the ascending aorta often occursIn bicuspid valves,ectasiais related to underlying defects in the aorta—with an imaging appearance similar to that in patients withMarfansyndromeDilatation also occurs because of the eccentric post-stenoticjet
Axial chest CT images in a 68-year-old woman show dense calcification of the aortic valve (top, arrow) and left ventricularhypertrophy(bottom,arrowheads).
Aortic Regurgitation (Insufficiency)
Most commonly related to aortic root dilatationRoot dilatation may be idiopathic or may be related to atherosclerosis due to aging or to anaortopathicsyndrome such asMarfandiseaseValvularcauses, which are less common, include:Bicuspid aortic valveRheumatic heart diseaseInfective endocarditisSeverely calcified aortic valves are oftenregurgitantResults in both left ventricular enlargement andleft ventricular hypertrophyBecause of enlargement, the ventricular wall may appear thin even when hypertrophied
Aortic Regurgitation (Insufficiency)
PA radiograph (above) and coronal CT image (right) obtained in a 48-year-old woman show a dilated aortic root and left ventricular enlarge-mentowing to aortic regurgitation.
Aortic Regurgitation
PA (left) and lateral (right) chest radiographs show marked left ventricular enlargement (arrows) in a 34-year-old woman with aortic regurgitation.
MarfanSyndrome
Coronal oblique (above left) and volume-rendered (above right) chest CT imagesshow anascendingaorticaneurysm in a 60-year-old woman. Note theannulo-aorticectasia, a classic feature ofMarfansyndrome. Thesinotubularjunction,which typically forms a waist in the ascending aorta, is effaced (flat). If the aortic root is dilated, aortic regurgitation may develop.Annuloaorticectasiaalso mayoccur in other hereditary aortopathies, such as a bicuspid aortic valve.
Aortic Annular Calcifications
Pathogenesis is similar to that of atherosclerosis in arteriesSame risk factorsHave no effect on valvular function
Lateral chest radiograph (left) and axial CT image (above) in an 81-year-old pa-tientshow aortic annular calcifications (arrows).
Tricuspid Regurgitation
Mild or trace tricuspid regurgitation is normalA majority of cases of pathologic tricuspid regurgitation are related to chamber abnormalitiesHeart failure or pulmonary hypertension with dilatation of the right ventricleLess common causes are endocarditis and carcinoid syndromeRecirculation within the right-sided chambers causes dilatation and hypertrophy of both the right atrium and the right ventricle; the effect is similar to that of mitral regurgitation on the left-sided cardiac chambersIncreased hepatic venous pressure can lead to cardiac cirrhosis
Moderate Tricuspid Regurgitation
Chest CT image (above) and PA radiograph (right) in a 62-year-old woman with mod-eratetricuspid regurgitation show right a-trial(RA)enlargement.RV= right ventricle.
RV
RA
RA
MHV
Axial CT images obtained in a 55-year-old man with shortness of breath and abdominal distention show a dilated right atrium(RA)and right ventricle(RV)with a tricuspidannuloplastyring (above left);nodular liverwith ascites (above right); and a di-latedleft ventricle(LV)due tononischemiccardio-myopathy.Biphasic hepatic vein waveform(right) from Doppler ultrasonography is consistent with severe tricuspid regurgitation and cardiac cirrhosis.
LV
RV
RA
Severe Tricuspid Regurgitation
Click to view animations
Pulmonic Stenosis
Results from a congenitally thickened or partially fused valveFrequently asymptomatic in children, commonly manifested in adulthoodA flow jet due to pulmonic stenosis is directed toward the main and left pulmonary artery and causes them to become enlargedObstruction also causes right ventricular hypertrophy
Patient with severe pulmonic stenosis andconse-quentmain and left pulmonary artery enlargement (arrow).
Pulmonic Stenosis
Axial chest CT images show a thickenedpulmonic valve(above left) in a patient with pulmonic stenosis. Note also the enlargement of themainandleftpulmonary artery (above right).
Endocarditis withVegetations
Endocarditis manifests with both embolic phenomena and valvular regurgitationPredisposing conditions include intravenous drug use and underlyingvalvulardiseaseSeptic emboli within the lungs may provide clues to the presence of endocarditisActualvegetationsare infrequently seen; rarely, a perivalvular abscess or pseudoaneurysm can develop, with potentially catastrophic consequencesRight-sidedvegetationsproduce pulmonary emboli;left-sidedvegetationsproduce systemic emboli
Axial chest CTimagesobtained in a 57-year-oldman with shortness of breath showaortic valvevegeta-tion(above left) andperipheralcavitarypulmonary nodules(above right). These findings are indicative of infective endocarditis and septic pulmonary emboli. Tricuspid and mitral valvevegetationswere seen at echocardiography(not shown).
Endocarditis withVegetations
Click to view animation
Endocarditiswith Vegetation
Axial chest CT images obtained in a patient with a fever after undergoing tricuspid and mitralannuloplastiesshow an ill-defined nodular region ofconsolidation consistentwithseptic emboli(above left)and avegetationon the tricuspid valve (above right).
Endocarditis with Septic Emboli
Bilateral, patchy, nodular areas of consolidation, some of which arecavitary,are suggestive of septic emboli.Cardiomegaly withright atrial enlargementissuggestive of tricuspidvalvulardysfunction.
Endocarditis with Septic Emboli
Axial pulmonary CT image shows bilateral,peri-pheral, ill-defined nodular areas of consolidation (arrows, above), some of which arecavitary. These findings are characteristic of septic emboli.Top right:Axial CT image shows thickening of thetricuspid valve leaflets,a finding that represents a vegetation, with right atrial(RA)enlargement due to tricuspid valve insufficiency.Bottom right:Axial CT image showssplenicandrenalembolic infarcts.
RA
Summary
Valvulardisease is common and can be identified on routine chest radiographs and CT imagesAortic valve diseaseCalcification of leaflets is associated with stenosisLeft ventricular hypertrophy may also be seenCalcification ofthe aortic annulusis usuallynotassociated withvalvulardiseaseAortic regurgitation is associated with a dilated aortic rootLeft ventricular enlargement and left ventricular hypertrophy may also be seenMitral valve diseaseCalcification ofthe mitral annulusis usuallynotassociated withvalvulardiseaseRegurgitationcauses enlargement of both the left ventricle andthe left atriumStenosis causes enlargement of the left atrium onlyPulmonary vascular redistribution may also be seenLeft atrial calcification is associated with rheumatic heartdisease(continues)
Summary
Tricuspid valve diseaseRegurgitation is associated with right ventricular and right atrial enlargementCan cause cardiac cirrhosis due to back-pressure on hepatic veinsPulmonic valve diseaseStenosis from congenital defect; direction of jet causes enlargement of the left pulmonary arteryEndocarditisManifests as embolic phenomena and valvular dysfunctionSeptic emboli are peripheral, ill-defined, nodular opacities that may show cavitationMay also see cerebral infarcts, renal infarcts,splenicinfarcts, or peripheral emboliRight-sided endocarditis: pulmonary emboliLeft-sided endocarditis: systemic emboliVegetationsare uncommonlyseen at non–cardiac-gated chest CTVegetationscausevalvularinsufficiency and may manifest with chamber enlargementPresence of emboli is the best clue todiagnosis(continues)
Summary
Note.―IVC = inferior vena cava.
Suggested Readings
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